Method of assembling silencers



Oct. 12, 1943.A G. JENSEN 2,331,325

y METHOD OF ASSEMBLING SILENCERS Filed Maren 28.` 1940 2 sheets-sheet 14 R. ew w w me Ww w i, A f f d M M Y B u n u 11u -Kw s) n) 41." w) 41u ww N mw RG mi... ,N ,rh F

` Ct. l2, 1943. G, JENSEN METHOD OF ASSEMBLING sILENCERs 2 Sheets-Sheet 2 Filed March 28, 1940 INVENTOR @lf2/,yar Jgzsezz 9' A TTORNE YS'.

Patented Oct. 12, 1943 METHOD F ASSEIWBLING SILENCERS Gunnar Jensen,

Jackson, Mich.,

assigner to Walker Manufacturing Company of Wisconsin, a corporation of Wisconsin Application March 28, 1940, Serial No. 326,455

3 Claims.

The present invention relates to silencing structures and, in particular provides an improved .process for assembling automotive silencers.

At the present time automobile silencers conventionally include an outer shell arranged for connection at one end to the exhaust pipe of the engine and arranged for connection at the other end to the usual tail pipe. Such outer shells conventionally enclose one or more tubular exhaust passages or conduits through which the exhaust l gases ow in traveling through the silencer.

It has been found exceedingly difficult with present day production methods to form up both the outer shell or shells and the inner conduit or conduits so that they are both of truly cylindrical or other desired shape, and so that they can be telescoped together in truly concentric, or other properly centered relation. Instead, it has been round that in forming up these elements, particularly the inner or primary exhaust conduit, such forming process introduces a longitudinal bow or arch therein. When the longitudinally bowed or arched conduit is introduced into its outer shell or shells, which may be assumed, for example, to be longitudinally straight, it will be understood that the inner conduit is not truly concentric, or otherwise properly centered, throughout its entire length, relative to the shell or shells. Other factors also make it diiiicult to arrange the conduit in properly centered relation to the outer lar embossments which extend radially outwardly from the main surface of the conduit. The em.- bossments are usually pressed from the body of the conduit before the latter is rolled into tubular form, and in many cases the embossment is not truly concentric with the conduit.

Due to the lack of concentricity, or other properly centered relation, between the conduit and the cooperating outer shell member, caused by the above or other circumstances, when the partition members are interposed between the conduit and the co-operating shell or shells, certain parts of the partitions bind upon the adjacent parts of the shell or conduit, thus interfering with the sliding action which is desired between the partitions and the shell. This difficulty is evidenced by the loud and objectionable clicking noise which usually accompanies the cooling down of a silencer structure. y

With the foregoing general considerations in view, the principal objects of thevpresent invention are to provide'an improved process of assembling silencers so as to effectively overcome the defects enumerated above, as well as other defects and t0 provide such a process of assembly characterized in that before being secured to a shell member or an inner conduit, the partitions are adjusted so as to compensate for any nonconcentricity between the outer shell and that part of the inner conduit which is engaged by the partition.

With the above as well as other objects in view, which appear in the following detailed description and in the appended claimsl a preferred but illustrative embodiment of the invention is shown in the accompanying drawings, throughout the several views of which corresponding reference characters are used to designate corresponding parts and in which:

Figure 1 is a view in longitudinal vertical section of a silencer embodying the invention;

Fig. 2 is a View in transverse vertical section, taken along the line 2-2 of Fig. 1;

Fig. 3 is a view in transverse vertical section, taken along the line 3-3 of Fig. 1;

Fig. 4 is a view in transverse vertical section, taken along the line 4-4 of Fig. 1;

Fig. 5 is a diagrammatic view in longitudinal section, illustrating the improved method of assembling the structure of Fig. 1;

Fig. 6 is a view in transverse vertical section, taken along the line 6-6 of Fig. 5; and

Fig. 7 is a view in transverse vertical section,

rtaken along the line 1-1 of Fig. 5.

Referring rst to Figures 1 through 4, the lllustrated silencer (to the structure whereof no claim is herein made) comprises an outer shell I0, a primary exhaustpassage or conduit I2, an intermediate shell I4, partitions I6, I8, 20, 22, 24, 2B, and 28, and end heads 30 and 32. The shell has a rolled seam 34 extending along one side thereof, and the heads 30 and 32, which serve to close the ends of the shell' I0, are provided with Vnipples 36 and 38, adapted for connection, re-

'as by means of a plurality of circumferentially the interior of the silencer into a plurality of sound absorbing silencing chambers. Partitions and 22 are rigidly securedyas by spot Welding at circumferentially distributed points, such vfasi 52 and 512, to the conduit l2, and their rounded outer peripheral surfaces 5S and e8 slidingly engage the inner surface of the outer shell ill. The partitions fi, 2G, and 23, in turn, are rigidly secured, as"by Weldingy at4 points such as Eidto the conduit i2, and their rounded outer peripheral surfaces, such as 62, slidingly engage 'the inner surfaceof the intermediate `shell iii.

y vConduit 'i2 'is provided with a plurality of v.groups/oi small openings "it, i2, lil, todo, land Si), which aiordv communication between the lfin- Yterior Vof -this conduit and the several silencing chambers into which the interior of the jshe1l^is divided bymeans of the previously mentioned 'partitions and the intermediate shell i4. n

[The silencing action Vproduced by the above structure "forms 'no part of "thepresent invention 'andA need not, therefore, be described.

'In `the operation of 'the above structure, the relatively hot gases passing in large partjdirectly "through the'inner conduit i2,. and in smaller part radially outwardly from this conduit into the above mentioned silencing chambersjheats Ithe several s tructural'elements of the silencer, causingv them to expand and contract. at differing rates and `to differing degrees; This expan- 'sion and contraction appears principally as changes inaXial lengths of the shells it and ill and the conduit i2,

By virtue of the aforesaid slidable connections, .a diierence'in degree fof longitudinal expansion orl contraction .of the inner conduit t2 ami the outershell i@ ory the intermediate shell lli, produces a sliding movement of vthe'fpartitions 26 and 22 'relative' tothe'outer shell, a sliding movementxoffthe partitions l,..and 2t relative tothe intermediate shell lli, and 'a sliding of the conduit l2 relativey to the nipple Similarly, while partition i'is rigidlysecured ,to both theoutershellf lil and the intermediate shell Hi, and While thecornpanion partition i8 Aisfrigidly'secured to lthe'intermediate shell lli, the latter partition is ,slidable relative to 'the outer shell iii. Consequently, diiering degree .of ,longitudinal expansion or contractionbe- 'ftv'veen the intermediate lshell It and the .outer shell 'l produce a sliding movement of the partition i8 relative tothe outer shell itl.

` In order to overcome by binding and resistance to said sliding, which, as aforesaid, results .from the irregularities produced 'in forming up the vsilencer' elements, it is *proposed in accordance yWith the present invention, lto eiect the assembly of a structure of the type shown in Figures l to 4, by iiist 'forming up the shell yand conduit members. into tubular form 'in accordance with `'the orior practice. Thereafter, the partitions, such as 2R22, 2li, 2G, and 28, associated with the innercGnduit l2. 'are iitted thereover and are This rounded surface isv seated uponv the embossments, such as H4, indi'-r vidual thereto. As will be understood, the embossments project radially from the surface of conduit i2 sufficiently to enable the annular par- 5 titions 23, 2L', 2li,- 26 and 23 to fit thereover from 0 plurality of annular surfaces such as 22, 24,

,. tt, E23, and i353, corresponding in number, longitudinal spacing, inside diameter, and form (in this case, cylindrical) to the corresponding shell I, jportionsvvith which the partitions 20, 22, 2li, and 2v2 `are to be associated. It Vbeing assumed ,as aforesaid, :that .the outer shell iii and the intermediate shell l can readily he formed into substantially true cylindrical forms, and thus :can be telescoped together in truly concentric 0 relation, it voll be understood that the annular surfaces `l 22,4 -i and lodare Yarranged longitudinally split, and'vtheupperand llower fparts l'ilu and Vli'ih are hinged together, fthus enabling the fixture toloe opened to permitr the conduit l2 and partitions 2l-i, "iid, and'fZB td'he inserted in place. Upon insertion- *o'f' lthe 'conduit l2 and its xassociated partitions into ithe fixture, it is "expected that by virtue of the? bow jin the Aconduit -iijor any Anon#concentricity of the embossinents "iii/fl or both'fthefouter peripheries of allor 'some `of the-partitions will be out 'oi concentric -relation'tothe "correspcnding'sur- 'faces 122, etc. Upon/closingtheiinture upon itself, however, 'the end portions i'andi off vthe Yxtureengage and solidly -supportthe 'ends of the conduit i'lin accurately concentric relation 40 tothe intermediate surfaces lfT2,etc. Thelclosjing movement fof the `fixture lalso enables 'lindividual surfaces vi"2'2, etc.'to-engage'ahd'itilt the respective partitions Q4,v ctc. V-relatii/"e fto Ithe conduit i2, thus bringing the roundedfouter :peripheral surfaces of 'these l'partitions into accurately `concentric relation to the surfaces fl'i' :and i3d, "and consequently, into accurately concentric yire lation to the respective endsof `title-conduit i2.

This tilting movement causes the reduced neck `'50 portionsuch-as ii-Zll of -each partition to slide! V4somewhatrelative to the corresponding oneness-- `mjent i'i'. It is-qjneierred that ithese neck' Aportions, 'such v`as have al relativei-y snug lirica tional it with lthe vc orresponding enibossn'ients;

ii il, so 'as'toy minimize -any'itendency to leakage .'betvveen the Aneclrportion and theernhossinent, 'but itis iound'in practice that "this snug tr-rela-- tively 'readily permits the required ftilting Amove ment Without defoim'ing either the partitions or 50 vthe embossinents.

v pri'sing theV electrodesV 155i) and 152, are introduced through openings,suc'has iiiajin theouter Wall oi the finiture 'and' longitudinally "through 'the yconduit ft2, vafter which such velectrodes .are v 'brought .together and `supplied vv'ith -welding ourrent so ias to form the previously mentionedspot vvelds and rigidly secure the oartitions tothe lovver tube in prcperlyadjustedfandaligned vp'ositions Itwill be noticed` that the-openings, such as "it, are 'distributed 4"circuniferen'tially '75 around the rxture, the lnumber of `suchopen'irrgs being determined, of course, in accordance with the number of spot welds which it is desired to provide at each partition. The openings |54 are also arranged in series, one such series of openings being provided adjacent each partition.

It will be understood that the completed assembly comprises a conduit I2 and its partitions can be inserted into an intermediate shell, such as I4, without introducing any binding between the partitions and the inner surface of the shell. It will also be understood that, in completing the assembly, partially assembled structure comprising the conduit I2, the intermediate shell I4, and the associated partitions, is introduced into the outer shell l0, after which the heads 30 and 32 are secured in place. This latter action brings the outer ends of the conduit I2 into accurately concentric relation to the shell I0. In View, however, of the fact that all outer peripheral partition surfaces which engage the shell I have been brought, by the previously described assembly process, into accurately concentric relation to the ends of the conduit I2, the securing in place of the heads and 32 does not introduce any binding between such partitions and the outer shell I0.

It will be recognized that the Surface bounded by the outer peripheral surface of each tilted partition, when viewed on a line at right angles to the axis of the silencer structure, is very slightly oval rather than being truly circular. It is found in practice, however, that by employing a proper conical angle in the partitions and also by employing the previously described rounded outer peripheral surfaces on the partitions, the surface so bounded by each tilted partition departs from a true circular form to only a negligible extent and that any such departure is readily taken up by the yieldability of the cooperating shell member and by the yieldability of the outer peripheral surface of the partition.

From the foregoing, it will be appreciated that the present invention provides an extremely simple and effective method of overcoming the binding heretofore encountered in structures of the type to which the invention relates. The present embodiment of the invention is to be regarded in an illustrative and not in a limiting sense.

What is claimed is:

l. The method of assembling a silencer structure comprising a pair of at least partially enclosed tubular members telescoped together in predetermined centered relation, at least one of the members being longitudinally deformed so that the ends thereof are not in proper alignment with portions intermediate such ends, said deformity being such that when the members are telescoped together the inner member is not properly centered throughout its length relative to the outer member, and further comprising at least one annular member extending between the said members at an intermediate point along their length, said annular member being disposed to slidably engage the other said member and to be nxedly secured to the said intermediate portion of the deformed member, which comprises fitting the annular member and the deformed member together, effecting a relative adjustment between ythe ends of the deformed member and the annular member sufficient to substantially compensate for said deformity and so as to bring the ends of the deformed member and that portion of the annular member which engages the other member into proper aligned relation to each other, securing said adjusted elements in said positions of relative adjustment, and thereafter assembling the deformed member and the annular member with the other member.

2. The method of assembling a silencer structure comprising a pair of at least partially enclosed tubular members telescoped together in predetermined centered relation, the inner one of the members being longitudinally deformed so that the ends thereof are not in proper alignment with portions intermediate such ends, said deformity being such .that when the members are telescoped together the inner member is not properly centered throughout its length relative to the outer member, and further comprising at least one annular member extending between the said members at an intermediate point along their length, said annular member being disposed to slidably engage the outer member and to be fixedly secured to the inner member, which comprises fitting the annular member and the inner member together, effecting a relative adjustment between the ends of the inner member and the annular member sufficient to substantially compensate for said deformity and so as to bring the ends of the inner member and that portion of the annular member which engages the outer member into proper aligned relation to each other, securing said adjusted elements in said positions of relative adjustment, and thereafter assembling the inner member and the annular member with the outer member.

3. The method of assembling a silencer strucm ture comprising a pair of at least partially enclosed tubular members telescoped together in predetermined centered relation, the inner one of the members being longitudinally deformed so that the ends thereof are not in proper alignment with portions intermediate such ends, said deformity being such that when the members are telescoped together the inner member is not properly centered throughout its length relative to the outer member, and further comprising at least one conical member extending between the said members at an intermediate point along their length, said conical member being disposed to slidably engage the outer member and to be fixedly secured to the said intermediate portion of the inner member, which comprises fitting the conical member and the inner mem,- ber together with a iit which is relatively snug but permits tilting of the conical member relative to the inner member without deforming either of said members, tilting the conical member by an amount suiicient to substantially compensate for said deformity and so as to bring the ends of the inner member and that portion of the conical member which engages the outer member into proper aligned relation to each other, securing the conical member to the inner member in said tilted position, and thereafter assembling the inner member and the conical member with the outer member.

GUNNAR JENSEN. 

